What-is-called calibration processing is performed in a vehicle or robot having a camera. The calibration processing includes checking the attached position and/or attitude of the camera and calibrates the difference from the designed value or values of the attached position and/or attitude of the camera. In general, the calibration processing is implemented by capturing a marker disposed in a predetermined position within a camera capturing range with the camera and using the position of the marker on the captured image, that is, the coordinates of a feature of the marker appearing in the image.
The marker to be used has a pattern which allows easy extraction of a feature from the captured image with the marker. For example, FIG. 12 illustrates an example of the form of the marker. A publicly known art has been available which allows extraction from a marker M1 having a form as illustrated in FIG. 12 the center of the pattern of the marker, that is, an intersection of boundaries forming different color areas as a feature. Reference may be made to Japanese Laid-open Patent Publication No. 2010-87743.